What do you guys think, did I find Road Tar or Undercoating?

I'll be the first say that this car is by No means an untouched survivor! It Is completely #s matching but poorly maintained and has been off the road since 1994. The exterior of the valance is sublime due to a sloppy backyard paintjob. The car was T-boned very early in its life and recieved a new replacement door and fender. Is this an over the counter valance?

Was the front valance already installed during paint at the factory? Was it necessary to remove the valance to install the front bumper? Why would the challenger process be different from what was used on the barracudas?

Tav